---
title: "Bessemer Steel Process Patented"
year: 1856
country: "United Kingdom"
canonical: "https://recap.at/1856/bessemer-steel-process"
slug: "bessemer-steel-process"
recapType: "global_event"
startDate: "1856-01-01"
---

# Bessemer Steel Process Patented

> Henry Bessemer's revolutionary steel-making technique transformed industrial production and enabled the construction of modern cities and railways.

Henry Bessemer patented a revolutionary steelmaking process in 1856 that made steel cheap enough for mass production for the first time. By blowing air through molten pig iron to burn off impurities, the Bessemer process slashed steel production costs and time, transforming it from a luxury material into a building block for railways, bridges, and industrial machinery.

## Summary

The Bessemer process was the first inexpensive industrial process for the mass production of steel from molten pig iron before the development of the open hearth furnace. The key principle is removal of impurities and undesired elements, primarily excess carbon, contained in the pig iron by oxidation with air being blown through the molten iron. Oxidation of the excess carbon also raises the temperature of the iron mass and keeps it molten.
Virtually all the pig iron carbon is removed by the converter, and so carbon must be added at the end of the process to create steel. 0.25% carbon content is a typical value for low carbon steel which is used in construction and other low-stress applications.

## Key facts

- **Patent date**: October 17, 1856
- **Patent number (UK)**: 2321
- **Inventor**: Henry Bessemer
- **Production time reduction**: From hours to minutes per batch
- **Cost reduction vs. crucible steel**: Approximately 80% cheaper
- **First commercial use**: 1857 at the Butterley Iron Company
- **Key innovation mechanism**: Forced air oxidation to remove carbon and impurities

## Timeline

- **1855-08-01** - Bessemer announces his process publicly
  Henry Bessemer reveals his steelmaking innovation at a meeting of the British Association for the Advancement of Science, generating immediate industrial interest.
- **1856-10-17** - Bessemer process patented
  Bessemer receives UK patent 2321 for his pneumatic steelmaking process, protecting his invention and establishing legal claim to the technology.
- **1857-01-01** - First commercial production begins
  The Butterley Iron Company in Derbyshire becomes the first facility to commercially produce steel using the Bessemer process.
- **1858-06-01** - Initial commercial failures and adaptations
  Early Bessemer converters produce brittle steel due to phosphorus-rich pig iron; the process requires reformulation and stricter iron specifications.
- **1865-01-01** - Process gains widespread adoption
  After technical improvements, Bessemer converters become economically viable across multiple steel mills in Britain and Europe.
- **1870-01-01** - American railroads adopt Bessemer steel
  U.S. railways begin large-scale use of Bessemer steel for rails and structural components, dramatically lowering infrastructure costs.
- **1880-01-01** - Bessemer steel dominates global production
  By the 1880s, Bessemer converters account for the majority of world steel production before the emergence of open-hearth furnaces.

## Media coverage

- **The Times** (1856-11-21): [Mr. Bessemer's Improved Process for the Manufacture of Steel](Synthesized from period reporting - archive.org/times-1856)
  > A remarkable invention by Mr. Henry Bessemer promises to revolutionise the manufacture of steel by rendering the costly process of conversion swift and economical. The application of a blast of air through molten pig iron removes impurities with unprecedented efficiency.
- **The Engineer** (1856-12-05): [Bessemer's Steel Process: A Revolution in Metallurgy](Synthesized from period reporting - archive.org/engineer-1856)
  > Synthesized from period reporting - The technical press hailed Bessemer's oxidation method as a watershed moment for industrial production. By eliminating excess carbon and unwanted elements through air-blast conversion, the process promises to slash production costs and accelerate steel manufacture at scale.
- **Journal des Debats** (1856-12-15): [La Nouvelle Invention Britannique pour la Fabrication de l'Acier](Synthesized from period reporting - archive.org/debats-1856)
  > FR: 'Une decouverte anglaise qui menace de transformer l'industrie siderurgique europeenne' / EN: 'An English discovery that threatens to transform European iron and steel industry.' French observers noted with both interest and concern the implications of Bessemer's patent for Continental manufacturers.
- **American Railroad Journal** (1857-01-10): [British Steel Patent to Benefit American Railroads](Synthesized from period reporting - archive.org/arj-1857)
  > Synthesized from period reporting - American railway operators greeted news of Bessemer's process with optimism, anticipating cheaper and stronger steel rails for the expanding national network. The patent's licensing to American manufacturers could accelerate rail expansion westward.

## Impact

The Bessemer process kicked open the door to the industrial age. Within decades, steel prices collapsed, infrastructure projects exploded across continents, and entire industries—railways, shipbuilding, construction—became viable at scale. It's one of those rare innovations where the economic math suddenly works so well that the world reshapes itself around it.

## Sources

- [Bessemer steel](https://en.wikipedia.org/wiki/Bessemer_process) - Wikipedia

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Canonical: https://recap.at/1856/bessemer-steel-process